Thermodynamic apparatus and method



Oct. 7, 1969 F, w, KANTQR 3,470,704

THERMODYNAMIC APPARATUS AND METHOD Tmzl.

Filed Jan. l0. 1967 BY awa; mfz@ ATTDR Oct. 7, 1969 F. w. KANTORTHERMODYNAMIC APPARATUS AND METHOD 4 Sheets-Sheet 2 Filed Jan. 10, 1967rrrrrrrrr a /L/ea Source 0ct. 7, 1969 F. w. KAN-ron THERMODYNAMICAPPARATUS AND METHOD 4 SheetsSheet 3 Filed Jan. 10, 1967 INVENTOR M% WmK A n@ i.,

FM l Oct. 7, 1969 F. w. KAN-ron THERMODYNAMIC APPARATUS AND METHOD 4Sheets-Sheet 4 Filed Jan. 10, 1967 /f/ 1/ ff /rf f r 1/ f4 /H/ /H f /f//f daf BY wwwa@ ATTO R United States Patent O 3,470,704 THERMODYNAMICAPPARATUS AND METHOD Frederick W. Kantor, 610 W. 114th St., New York,N.Y. 10025 Filed Jan. 10, 1967, Ser. No. 608,323 Int. Cl. F25b 3/00 U.S.Cl. 62-115 39 Claims ABSTRACT OF THE DISCLOSURE A working uid is rotatedin a rotary enclosure with the fluid moving rst away from and thentowards the axis of rotation in a closed loop within the enclosure. Thefluid is moved in its closed-loop path by means of a thermodynamic pumpwhich makes use of the differing densities and diiferential centrifugalforces on the working uid to pump the uid through the conduit.Troublesome rotary gas seals are not used, and a working uid having arelatively high density can be used in order to minimize the rotationalspeeds required. Also, the working fluid can be given a relatively highinitial pressure. In one embodiment of the invention the working fluidchanges between the gaseous and liquid states, and in anotherernbodiment heat is transferred between portions of the loop atdifferent radii to provide very low refrigeration temperatures.

This invention relates to thermodynamic apparatus and methods; moreparticularly, the present invention relates to highly ecient apparatusfor refrigeration and heating.

A theoretically highly eflicient but impractical refrigerator device hasbeen proposed in U.S. Patent 2,393,338 to J. R. Roebuck, and A NovelForm of Refrigerator, 16 Journal of Applied Physics 285-295, May 1945,by J. R. Roebuck. The basic form of the device proposed by Roebuck isshown in FIGURE 1 of the drawings. The tube 10, which is supported inbearings 12, is rotated at a very high speed about a central axis 14, asindicated by the arrow 16.

Compressed air is introduced into the tube at its inlet 18. The gasmoves radially outwardly from the axis 14 between points 20 and 22 inthe tube. While doing so, the gas is compressed and heated by thecentrifugal force created by the rotation. During its movement betweenpoints and 22, the gas is cooled by means of water flowing in coolingcoils (not shown) so that temperature of the gas remains substantiallyconstant.

While traveling between points 22 and 24, the gas is unaffected by therotational motion. However, while moving from point 24 to point 26 thegas expands and becomes substantially cooler. The cold gas then flowsout of the outlet opening 28 for use in refrigeration.

One aspect of the above-described prior art thermodynamic system ishighly attractive. In theory, its thermodynamic cycle approaches a trueCarnot cycle and thus is highly efcient. However, the equipment actuallyproposed for this system is highly impractical since it requires theprovision of a separate mechanical gas compressor, and requiresexpensive and troublesome gas seals at the inlet to and the outlet fromthe rotating member v10. Furthermore, extraordinarily high rotatingspeeds of the order of 100,000 to 200,000 r.p.m. are required in orderto provide effective operation. These deficiencies have been so severethat, it is believed, the device has not been commercially adopted toany substantial extent.

In accordance with the foregoing, it is an object of the presentinvention to provide thermodynamic apparatus and methods utilizingcentrifugal force, which apparatus and methods do not require auxiliarymechanical compressors or gas seals, and do not require excessively highlCe rotational speeds to develop suicient centrifugal forces. It is afurther object of the present invention to provide such apparatus andmethods which are highly etlicient, and to provide apparatus which iscompact and relatively simple and inexpensive to build and maintain.

In accordance with the present invention, the gas seals and mechanicalcompressor are eliminated by moving the working uid in a closed looppath within a rotor by means of a thermodynamic pump. The requirementfor high rotational speeds is eliminated by using a working lluid ofrelatively high density and, in one embodiment of the invention,changing a gas into a liquid and then back into a gas again. The workingfluid can be sealed in the closed loop at relatively high initialpressures, if desired. Other features of the invention are described indetail in the following description.

The drawings and description that follow describe the invention andindicate some of the ways in which it can be used. In addition, some ofthe advantages provided by the invention will be pointed out.

In the drawings:

FIGURE l is a schematic diagram of a prior art device;

FIGURE 2 is a schematic diagram of a device and method in accordancewith the present invention;

FIGURE 3 is a perspective, partially broken-away and partially schematicview of the thermodynamic device shown schematically in FIGURE 2;

FIGURE 4 is a schematic diagram of another embodiment of the presentinvention;

FIGURE 5 is a perspective, partially broken-away and partially schematicview of the device shown schematically in FIGURE 4;

FIGURES 6 and 7 are graphs showing the qualitative variations of variousoperational parameters of the device shown in FIGURES 2 and 3; and

FIGURES 8 and 9` are schematic diagrams of two other embodiments of thepresent invention.

FIGURE 2 is a schematic diagram of a portion of the completethermodynamic device shown in FIGURE 3, and is used to facilitateexplanation of the principles of operation of the invention.

The structure defining the working fluid flow conduit in FIGURE 2includes a shaft 30 with a hollow flow passage 32 for the working fluid,and solid end portions 34 and 36. Several tubes, indicated generally at37, are connected between the opposite ends of the central conduit 32 ofthe shaft 30. However, only one such tube is shown in FIGURE 2 in orderto simplify the drawing.

The tube 37, which is made of a suitably thermally conductive material,includes a first section 38 which extends radially outwardly from theleft end of conduit 32, a second section 40 which extends back towardsthe rotational axis 41 of the shaft 30 at an acute angle to the axis.Another section 42 extends radially towards the axis 41, a furthersection 44 extends parallel to the axis 41, and another section 46extends outwardly at an acute angle from the axis 41. A section `48 thenproceeds radially inwardly towards axis 41, and a final section 50extends towards axis 41 at an acute angle and communicates with theright end of conduit 32.

The conduit 32 and the tube 37 connecting its ends together comprise aclosed loop conduit for carrying the working medium. The tube sections38, 40 and 42 cornprise a thermodynamic pump, indicated at 51, forpumping the fluid through the conduit in the direction indicated by thearrows, and the tube sections 46, 48 and 50 comprise a refrigeratorsection, indicated at 53,which operates on the same principles as theprior art device shown in FIGURE 1.

In accordance with one aspect of the present invention, the working uidpreferably is a gas of a density which is high relative to the densityof air. Suitable highdensity gases are well known in the art. Forexample, each of the refrigerants comprising flurochloromethane andflurochloroethane and sold under the trademark Freon by Du Pont has adensity several times greater than that of air under standard conditionsand is quite suitable for use as a working uid in the present invention.As will be explained in greater detail below, the use of high-densityfluids significantly reduces the speed at which the loop must berotated.

The thermodynamic system shown in FIGURE 2 operates as follows: theshaft 30 is rotated about its axis 41 as indicated by the arrow 52.Centrifugal force created hy the rotation compresses the iiuid insection 38. Section 38 is insulated so that the gas is compressed in itsubstantially adiabatically; that is, without the gain or loss of heatthrough the walls.

The changes in gas pressure and volume are shown qualitatively in FIGURE7. The starting point in the diagram of FIGURE 7 is located at the samedistance R1 from the axis 41 as the center of tube portion 44. At thatpoint in tube 38 the gas pressure and temperature are P1 and T1. At agreater radius R2, the gas has been compressed to a pressure P2, and itspressure thus has been increased by an amount APa. As is shown by FIGUREl6, which qualitatively illustrates the variation of gas temperaturewith conduit radius R, the temperature T2 at the radius R2 also issubstantially increased over the temperature T1 due to compression ofthe gas.

When the gas ows back towards axis 41 in section 40, the gas pressuredecreases as the radial distance decreases. Simultaneously, thetemperature of the gas tends to decrease due to expansion of the gas,and this would reduce the expansion compared to the isothermal case.However, heat is added to the gas from a heat source S4 so that the gasexpands isothermally and has a lower density than it otherwise wouldhave had. The angle at which the tube section 40 is inclined withrespect to axis 41 is set at a value such that the amount of heat addedby heat souce 54 will maintain the temperature in the gas constant alongthe entire length of tube 40, thus providing isothermal expansion of thegas along section 40. Although the tube 40 is shown as a straightsection in FIGURE 2, it should be understood that it may have a complexcurved shape in order to ensure that the expansion of the gas isisothermal at all points along section 40. Adiabatic changes in thestate of the gas are indicated by A symbols in FIGURES 6 and 7, andisothermal changes are indicated `by I symbols.

The tube section 42 extends toward axis 41 from a radius R3 to radiusR1. Tube sections 42 and 44 are insulated so that expansion of the gastherein is adiabatic. Referring again to FIGURES 6 and 7, the gas at theinnermost end of section 42 has a pressure P4 and a temperature T3. Thedifferent densities of the gas in the sections 38 and 40-42 creates apressure difference which is greatly augmented by the action ofcentrifugal force on the columns of gas. The pressure P4 is less thanthe pressure P2 at the outermost end of tube 38 by an amount APa minusAPb (see FIGURE 7). This pressure difference is the pumping pressureprovided by the pumping unit 51.

The temperature T3 of the gas in tube section 44 preferably isapproximately equal to that of the ambient medium. In tube section 46,the gas is again compressed, but is cooled by heat transfer to theambient medium so that its temperature is maintained substantiallyconstant; for example, to Within ve or ten percent of the temperatureT3. Thus, as is indicated in FIGURES 6 and 7, the gas is compressedisothermally to a higher pressure P at a radius R4. Water or otherliquids can be used as coolants instead of air, as is well-known in theprior art.

The gas then is expanded adiabatically in section 48 to a lower pressurePG and a lower temperature T4. In section 50, the gas further expandsisothermally, and eventually ows through the axial conduit 32 andeventually returns to the initial pressure and temperature P1 and T1.Sections 32 and 48 are insulated to provide adiabatic conditions. Theexpansion in section 50 is made substantially isothermal by extractingheat from the ambient medium by heat transfer to the gas. The arrow 56indicates the flow of ambient air either toward or away from the axis104 along and in contact with section 50, thus providing the heattransfer desired. The cold air then is used for air cooling orrefrigeration, as desired.

It is to be noted that a positive pressure is created in the gas insection 46, and a negative or back pressure is created in sections 48and S0 due to the differing densities of the gases as acted on bycentrifugal force. The negative or back pressure is greater than thepositive or forward pressure. This excess of back pressure tends tooppose the forward pressure produced by the pumping section 51 and thustends to oppose the llow of uid in the conduit. However, the forwardpumping pressure always is greater than the back pressure and the gasows around the closed loop in the direction indicated by the arrows inFIGURE 2. The process is thermodynamically reversible, thus indicatingits high efficiency.

The device and method described above can be used in heating as well asrefrigeration. For example, in a home heating system, the heat sourcecould be the home furnace, the cold end of the device would communicatewith the air outside the house, and the heat dissipated in isothermallycompressing the working uid in conduit section 46 would be used to heatthe air in the house. Such a system would have the high thermodynamiceiciency lacking in present systems but would not have excessivecomplexity. Other arrangements using the invention in heating may beprovided in accordance with the prior art.

It is an advantage of the present invention that the maximum radius ofthe rotor can be made relatively small (e.g. 2 to 4 inches) even thoughthe rotational speed of the device is low (eg. 1,000 to 3,000 r.p.m.).The amount of compression provided by the device is a function of themaximum radius of the ow conduit and the density of the working fluid.By the use of a high-density working uid such as the Freon gasesdisclosed above, the required rotational speed and the maximum conduitradius are minimized. In fact, the rotational speed is brought withinthe realm of practicality by the present by reducing the required speedfrom the 100,000 to 200,000 r.p.m. speed previously required to thevicinity of 1,000 to 3,000 r.p.m. An important advantage of thisreduction in rotational speed is that heat can be conducted into and outof the rotating system by simple fins instead of the elaborate liquidconduit system required in the prior art devices. These fins move with avelocity compatible with their utilization as impeller blades for movinggases through the cold and warm air ducts external to the rotatingassembly. What is more, by providing a closed loop conduit containedentirely within the rotating device, troublesome seals are not requiredfor passing the working fluid into and out of the rotating system. Thisgreatly saves in complexity, maintenance, and cost of the device, andmakes it possible to use high-density working fluids and seal them inthe closed loop at relatively high pressures.

The entire thermodynamic device shown in FIGURE 3 comprises a rotorstructure generally indicated at 58 and a motor 60 (illustratedschematically) which drives the rotor structure 58. Suitable bearings(not shown) are provided at ends 34 and 36 of the central shaft 30. Itis another advantage of the present invention that the motor 60 need notbe very powerful, since its only function, after driving the rotor 58 upto its operating speed, is to maintain it at the speed attained and todrive the fan blades secured to the rotor. Maintaining the speed of therotor requires very little energy from the motor since the source ofenergy for the thermodynamic system is the heat source 54, not themotor.

As is shown in FIGURE 3, the gas flow tubes 37 are arrangedsymmetrically about the axis of rotation 41. It is indicatedschematically in FIGURE 3 that three pairs of opposed tubes 37 (sixseparate tubes) are provided in the device shown. However, the number ofseparate tubes provided is optional.

Each tube 37 is secured at each end in a manifold structure 62 securedto the outside of shaft 30. Each tube communicates with the conduit 32by means of a separate port 64 extending through the side-wall of theshaft 30. The thickness of the side-wall of the shaft 30 is maderelatively great so as to give it sutiicient structural strength despitethe weakening effects of the ports 64.

The rotor 58 includes a first housing section 66, preferably of metal,which extends around the pump portion 51 of the structure and isinsulated from the gas fiow conduits by means of insulation 68 at allplaces except along the tube section 40. The metal of the housing makesintimate contact with the metal of the tube section 40. A plurality ofradial heat-transfer fins 70 extends from the outer surface of housingsection 66.

A stationary gas guidance arrangement 74 is mounted on a suitableexternal support structure (not shown). The structure 74 has a rstannular guide member 76 which extends around the housing 66 and isspaced at a relatively great distance from the housing. Positioned tothe right of plate 76 is an insulating member 78, also of annular shape,which closely tits the contours of an external section 80 of insulationwhich covers tube sections 42 and 44. Hot air (or other gas) isintroduced between the insulating member 78 and the plate 76 and owstowards the iins 70. The fins 70 have holes 72 spaced around theirperiphery which catch the heated air and pass it from one fin to thenext and throw the air radially outwardly after its heat has beentransferred to the tube sections 40 in the rotor. The structure 74includes another annular plate 82 spaced to the right of insulatingmember 78 which guides cool air towards a plurality of fins 84 withholes in them which are secured to the outside of another metal housing86 which makes intimate contact with the portion 46 of the gas flowconduit. The cool air is transferred through the holes in the ns fromone iin to the next and is thrown outwardly after heat has beentransferred to the air.

Another metal housing 87 makes intimate contact with the sections 50 ofthe gas flow tubes, while the tube section 48 is insulated by means ofinsulation 88. A plurality of fins 89 extend from the housing 86.Another annular insulating ring 91 extends around and in close proximityto the insulation 88. The ring 9.1 separates the iins 84 from the fins90 in order to insulate the gas flows to and from those sets of finsfrom one another. Each iin has a plurality of inwardly-bent bladeportions 92 which act as fan blades to push the cold air forward asindicated by the arrows 94. Warm air is drawn in towards the fins 90from the atmosphere, is cooled due to contact with the cold tubeportions 50 and fins 92, and then is pushed outwardly by the fan blades92. As is well known in the art, many other forms of heat exchanging nscan be used here, and gas ows can be directed as desired.

The device shown in FIGURE 3 is ideally suited for air conditioning orrefrigeration, and is especially valuable in applications in which aheat source already is available, such as in automobiles and similarequipment. Heat can be obtained from the engine of the automobile, andthe warm air given oif by the device can be expelled from the car. Theair to be cooled is taken from the interior or exterior of the car, iscooled, and then is circulated in the car. Thus, a simple, compact,self-contained and relatively inexepnsive automobile air cooler isprovided.

The radii, rotational speed, initial pressure at which the iiuid issealed in the device, and selection of working fluid advantageously canbe varied quite readily in order to adjust the operation of the deviceto adapt it to specific uses. The Working fluid desirably should beselected so 6 that it will not liquify at the speeds and radii selected.However, in the embodiments shown in FIGURES 4, 5 and 8, the gas, radiiand rotational speed are selected so as to deliberately produceliquefaction of the working gas.

In the device shown in FIGURES 4 and 5, the refrigerant gas, preferablyFreon, is selected to liquify `at a chosen pressure and temperature, andthe maximum radius of the flow conduit and the rotational speed of therotor are selected so as to liquify the gas at a given radius, whilemaintaining it in a gaseous state at the axis.

Referring iirst to the schematic diagram of FIGURE 4, the device 100includes an axial tube 102 which communicates at its open ends with aplurality of radial conduits extending outwardly from the axis ofrotation 104 of the tube 102 and communicating with reservoirs near the-outermost surface of the device. Only one set of conduits andreservoirs is shown in FIGURE 4 for the sake of simplicity.

The gas in the axial tube 102 flows into a first radial conduit orpassageway 106, and, because of the high density of the gas, the radiusand rotational speed of the de vice, and the type of gas used, the gasliquiiies at some point along the conduit. The liquid then iiows into areservoir or chamber 108 in which it collects. Chamber 108 has an outersurface 111 which extends in a direction generally parallel to therotational axis 104. A heat source 110 delivers heat to surface 111 inorder to heat the liquid and cause it to boil and return to the gaseousstate. The chamber 108 provides a relatively broad external heattransfer surface 111 and la relatively large liquid surface area fromwhich to boil gas.

The gas boiling out of chamber 108 flows inwardly towards axis 104through a conduit 114, and cools due to expansion resulting from thereduction of centrifugal force on the gas. The gas then passes intoanother conduit 116 extending radially outwardly and again is compressedby centrifugal force and again liquies, The liquid flows from conduit116 into a second chamber 118 which has an outside surface 120 extendingin the direction of the laxis 104. Heat is extracted from the condensingfluid at surface 120 and the liquid iiows through an expansion nozzle122 into a third chamber 124. Due to the heat loss of the liquid inchamber 118 and its flow through the expansion nozzle 122, part of theliquid evaporates into a gas in chamber 124, Iand part of it iiowsthrough the nozzle 122 in liquid form and collects at 126 on the insideof the outer wall 128 of chamber 124. Heat is extracted at surface 128from the uid or object being cooled, and the liquid 126 evaporates andpasses through the inwardlydirected radial passageway back to theconduit 102 to complete a closed loop flow path. The evaporation of theliquid in chamber 124 cools the liquid 126 and the surface 128 andprovides excellent refrigeration,

The liquid and gas are driven around the closed loop by a pump relatedto that used in the embodiment shown in FIGURES 2 and 3. The passages106, 108 and 114 constitute a pump section. The liquid and gas inpassage 106 has a far greater density than the gas in passage 114. Thus,the pressures created by centrifugal force on the iiuids in passage 106far exceed the pressures from the gas in passage 114 and the resultingpressure difference pumps the fluids around the closed loop.

This embodiment of the invention has an advantage in that the outersurfaces 111, 120 and 128 of the liquid chambers 108, 118 and 124 formrather broad surface areas for maximizing the rate of heat transfer. Theheat transfer is further improved by the fact that each surface is incontact with a liquid which is thrown .against it with great force. Theliquid conducts heat much better than a gas. Insulation of the passagesand chambers is provided in all places where heat transfer is notspecifically desired so as to maximize the efficiency of the device.

The chambers 108 and 124 are shown in FIGURE 4 as being located atgreater radii than the chamber 118. This is `done merely to illustratethat the radial position of each `of the chambers 108, 118 and 124 canbe adjusted as required for the particular thermodynamic use to whichthe equipment is to be put.

The construction of the complete thermodynamic device 100 is shown inFIGURE 5, and includes a plurality of radial Spacers 132, preferably ofthermal insulating material, each of which abuts the tube 102 at oneedge and extends outwardly to the outer surfaces 111, 120 and 128 of theliquid chambers 108, 118, and 124. The spacers are longer than the tube102 and abut at their ends against insulating end plates 134 and 136,each of which has a centrally-located shaft member 138 or 140. Thisconstruction effectively separates the rotor into a plurality of radialcompartments (16 compartments in the specific device shown in FIGUREeach of whose cross-section is shaped like the sector of a circle. Theseparators 132 are provided so that the liquid and gases flowing in thepassageways in a radial direction will not swirl in the rotor due toCoriolis forces. A motor 142 rotates the rotor 100 at the desired speed.

Each of the spacers 132 preferably has a plurality of large holes asindicated at 144, 146 `and 148 in order to minimize its weight andprovide access for filling the spaces around the flow passages withinsulation material.

A iin 150 without holes, and a plurality of other fins 152 extendoutwardly from the Surface 111 of liquid chamber 108. Each n 152 has aseries of peripherallyspaced holes 154. Another fin 156 without holes isprovided at the far right edge of the surface 111. A stationary air`duct is formed by a pair of parallel annular plates 158 and 160 whichextend around the unit 100 in close proximity to the center ns on thesurface 111. Hot air is introduced into the passageway formed betweenthe plates 158 and 160 and flows between the fins by means of holes inthe fins, and then is thrown `outwardly after it has transferred itsheat to the ns.

A plurality of other radial fins 162 with holes in them extend from theouter surface 120 of chamber 118. A solid fin 166 is positioned at theleft edge of surface 120 and is joined with the n 156 on surface 111 bymeans of insulation material 164. Another annular plate 168 and anannular insulation member 170 guide cool air towards the ns 162. The airpasses through the holes in the ns and outwardly after absorbing heatfrom the fins and the surface 120. Another stationary annular insulator171 extends around and near the insulator 164. Insulators 170 and 171serve to insulate adjacent fins and the related air flows from oneanother.

Fins 172 protrude from the surface 128 of chamber 124. Air is drawn fromthe ambient medium into the fins 172 and is blown outwardly in thedirection of the arrows 173 by means of fan blades 174 formed in the ns172 in the same manner as the blades 92 are formed in the ns of theFIGURE 3 device. The ns 172 conduct heat from the ambient air into theliquid 126 in the chamber 124, thus cooling the air and evaporating theliquid. The cold air then is used for refrigeration. Of course, thedevice 100 also can be used for heating, in substantially the same wayas the device shown in FIGURES 2 and 3.

A further advantage of the structure shown in FIG- URES 4 and 5 is thatit has considerably greater total area for heat transfer in the samevolume occupied by the structure shown in FIGURES 2 and 3. Also, theradial separators 132 improve the strength of the structure.

The embodiment shown in FIGURE 8 is identical to that shown in FIGURES 4and 5 except that a gas pumping unit 175 like the unit 51 shown inFIGURE 2 replaces the liquid pumping unit shown in FIGURE 4. Morespecifically, an angular passage 176 and a straight passage 178 replacethe chamber 108 and the passage 114, respectively. The distances ofchambers 118 and 124 from the axis 104 can be adjusted to suit thedesired thermodynamic operating conditions. The radial dimensions ofpumping unit 175 are made greater than those of the chambers 118 and 124in order to maximize the pumping pressure provided by the pumping unit.However, the working uid, initial pressure and other variables areselected so that the working uid in passages 106, 176 and 17 8 remainsin a gaseous state at all times despite the fact that the fluidliquefies in chamber 118 which may be at a smaller radius. Thedifference is that heat is extracted in chamber 118, but not in the pumpsection. The gas pumping section provides pressure for forcing theliquid and gas around the closed loop in the same manner as described inconnection with FIGURE 2.

FIGURE 9 illustrates another embodiment of the invention which isidentical to that shown in FIGURES 2 and 3 except that an elongatedconduit section 180 parallel to axial section 32 is provided togetherwith a plurality of thermally conductive washers 182 separated from oneanother by insulation 184. Also, only the section 50 returns the section180 to the axis, and the radial section 48 is not provided. Thus, themovement of the gas through section 50 is substantially isothermal so asto maintain reversibility of the processes of cooling and ofregenerative heat exchange. The gas in section 180 conducts its heat toopposite, relatively short portions of the tube 32 through themutually-insulated washers 182 and thus is pre-cooled by the cooling ofthe system in a thermal feed-back or regeneration arrangement. Thisenables the provision of very low cold temperatures in section 50, andmakes the thermodynamic device quite valuable for use in theliquefaction of gases and other uses in which very low temperatures arerequired.

Alternatively, the washers 182 may be made of insulating material andthe spaces between them filled with either a liquid or gas instead ofsolid insulation 184. Radial spacers (not shown) such as the spacers 132shown in FIGURE 5 can be -used to prevent `Coriolis swirling of the uidsin the spaces. The fluids provide the heat transfer between sections 180and 32 instead of the washers. The fluids preferably are different fromthose flowing in the closed loop, and/or are stored at differentpressures to maximize heat transfer.

One of the important advantages of the invention is that there is asufficient number of adjustable parameters to permit the thermodynamicoperation to closely approximate a Carnot cycle operating between threearbitrarily chosen temperatures. By the addition of a multi plicity ofthermally conductive sections in the closed conduit system, heat can beexchanged isothermally with a multiplicity of external reservoirs atvarious temperatures.

Many different and well known heat sources and means of heat transfercan be used: for example, a system for use in space could have areflector for gathering solar energy, and ns for radiating heat from theintermediate temperature section. Once the rotor had been set intorotation, very little energy would be required to maintain its rotation.As an alternative, a radio-isotope source could be used as a heatsource.

The above description of the invention is intended to be illustrativeand not limiting. Various changes or modifications in the embodimentsdescribed may occur to those skilled in the art and these can be madewithout departing from the spirit or scope of the invention as set forthin the claims. Thus, it should be apparent that the invention is notlimited to the specific structures illustrated in the drawings. Forexample, each of the various embodiments can be constructed inaccordance with the structural concepts shown in the other embodiments,and these concepts may be used in combination with one another, allwithout departing from the invention.

I claim:

1. Thermodynamic apparatus comprising, in combination, a rotor, meansfor rotating said rotor, conduit means in said rotor for defining aclosed loop fluid flow conduit within said rotor, said conduit having afirst section extending away from the axis of rotation of said rotor, asecond section extending toward said axis, and a third section joiningsaid first and second sections, means for removing heat from a fluid insaid third section, and pump means for urging the flow of said fluidthrough said closed loop, said pump means comprising means for creatinga continuous difference between the average density of a first volumeelement of fluid in said first section and a second volume element offluid in said second section, said first and second volume elementsbeing equal and being located at equal average radial distances fromsaid axis.

2. Apparatus as in claim 1 in which said pump means includes means forheating said fluid at a location spaced outwardly from said axis.

3. Apparatus as in claim 2 in which said third section includes fourthand fifth sections of said conduit, said fourth section being connectedto said second section and extending outwardly from said axis ofrotation of said rotor, said fifth section being connected between saidfourth and first sections and extending inwardly toward said axis, saidheating means being positioned to conduct heat to said second section toheat the fluid therein.

4. Apparatus as in claim 3 in which said second section extends towardssaid axis at an acute angle whose magnitude is such that the temperatureof the fluid in said second section remains substantially constantthroughout said second section for a given rate of heat input to saidsecond section.

5. Apparatus as in claim 4 including a sixth section of said conduit,said sixth section extending radially toward said axis at the end ofsaid second section.

6. Apparatus as in claim 5 including thermal insulation material aroundsaid first and sixth sections.

7. Apparatus as in claim 1 including an expansion nozzle in said thirdsection.

8. Apparatus as in claim 3 including an expansion nozzle in said thirdsection.

9. Apparatus as in claim 8 including first, second and third liquidreservoirs, each located in one of said fourth, second and fifth conduitsections and having a thermally conductive outer surface extending inthe direction of said axis of rotation.

10. Apparatus as in claim 3 in which said third section includes a sixthsection which extends along the rotational axis of said rotor, andincluding a seventh section radially spaced from said axis and joiningsaid fourth and fifth sections, said seventh section extending in adirection substantially parallel to said axis, and a plurality oflongitudinally spaced and mutually insulated heat conducting means eachof which is coupled between said sixth and seventh sections.

11. Apparatus as in claim 10 in which each of said heat conducting meanscomprises a radial fin, and including insulation between adjacent fins.

12. Apparatus as in claim 3 including first and second axially-extendingchambers with thermally-conductive outer surfaces, an expansion nozzlejoining said chambers, the first of said chambers `comprising saidfourth conduit section, the inlet end of said first chamber beingconnected to the outlet of said second section, and lthe outlet of saidsecond chamber being connected to the inlet of said fifth section, a gassealed in said closed loop, the system parameters, including the type ofsaid gas, the radii of said sections and said chambers, and the rate ofheat transfer to said second section and from said fourth section beingsuch that said gas is a liquid in said chambers but is a gas in saidclosed loop along said axis, and in said fifth section.

13. Apparatus as in claim 12 in which the maximum radius of said firstsection is substantially greater than that of either of said chambers,said parameters being such that said gas also is in a gaseous state insaid first and second sections.

14. Thermodynamic apparatus comprising, in combination, a rotor, meansfor rotating said rotor, conduit means in said rotor having a firstsection for guiding the flow of fluid radially outwardly from the axisof rotation of said rotor, and a second section connected to said firstsection at a location spaced radially outwardly from said axis forguiding the flow of fluid back towards said axis, further conduit meansjoining; said first and second conduit sections to conduct a fluidtherebetween at a second location which is spaced inwardly towards saidaxis from said first location, means for creating a continuousdifference between the average density of a first volume element offluid in said first section and a second volume element of fluid in saidsecond section, said first and second volume elements being equal andbeing located at equal average radial distances from said axis, andmeans connected to said conduit means for pressurizing and thenexpanding the fluid.

1S. Apparatus as in claim 14 in which the fluid in at least one of saidconduit sections is a liquid.

16. Apparatus as in claim 14 including gas liquefaction means forliquefying a gas in said conduit.

17. Apparatus as in claim 14 in which said differencecreating meansincludes an energy-developing flux source located externally of saidrotor, and means for supplying energy to said fluid from said fluxsource by directing said flux through the walls of said rotor.

18. Apparatus as in claim 17 in which said energydeveloping flux sourceis a heat source, and said flux is heat flux.

19. Apparatus as in claim 14 including means for conducting heat fromthe ambient medium into the fluid in said second section.

20. Apparatus as in claim 19 in which said heat-conducting meanscomprises a plurality of fins with angularly canted portions to serve as`fan blades to move the cooled ambient gas.

21. Apparatus as in claim 14 including a gas hermetically sealed in saidconduit.

22. Apparatus as in claim 31 in which said gas has a densitysubstantially greater than that of air.

23. Apparatus as in claim 22 in which said gas is selected from thegroup consisting of fluorochloromethane and fluorochloroethanerefrigerants.

24. A thermodynamic process comprising the steps of subjecting a fluidto centrifugal force at a first station in a rotary conduit to compresssaid fluid, simultaneously cooling said fluid to maintain said fluid ata substantially constant temperature while being compressed, reducingthe centrifugal force on said fluid at a second station in said conduitto expand and cool said fluid, and heating said fluid at a third stationin said rotary conduit to create a continuous difference between theaverage densities of first and second volume elements of said fluid indifferent radial portions of said conduit and to cause said fluid toflow from said first station to said second station.

25. A process as in claim 24 including the steps of precompressing saidfluid at a fourth station by the application of centrifugal forcethereto prior to said heating step, and then reducing said centrifugalforce at said third station simultaneously with said heating of saidfluid.

26. A process as in claim 25 in which said simultaneous heating andcentrifugal force-reducing steps are controlled so that the temperatureof said fluid remains substantially constant during said steps.

27. A process as in claim 26 including the step of substantiallyadiabatically expanding said fluid between said third and firststations, and in which the expansion of said fluid at said secondstation is :at least partially substantially adiabatic and partiallysubstantially isothermal.

28. A process as in claim 24 in which heat is exchanged between each ofa plurality of thermally insulated positions on two portions of thefluid located at different radii in said rotary conduit.

29. A process as in claim 24 in which said fluid is cooled by -heattransfer to another fluid desired to be heated.

30. A thermodynamic process comprising the steps of rotating a closedloop fluid conduit with a fluid therein, creating a difference betweenthe average density of said fluid along a first segment of fluid flowingoutwardly from the axis of rotation of said conduit and the averagedensity of said fluid along a second segment of fluid flowing inwardlytoward said axis, said segments being of equal radial length and beingspaced from said axis at equal distances, using the centrifugal forceapplied to said fluid to compress it in one section, removing heat fromsaid fluid simultaneously with said compression step, and allowing saidfluid to expand and cool by reducing the centrifugal force on said fluidat another section.

31. A process as in claim 30 in which the average density of the fluidin said first segment exceeds that of the fluid in said second segment.

32. A process as in claim 31 in which the fluid in said first segment isa liquid and the fluid in said second segment is a gas.

33. Thermodynamic apparatus comprising, in combination, a rotor, ahollow member on the rotational axis of said rotor and extending beyondthe ends of said rotor to serve as a drive shaft therefor, a manifoldstructure encircling each end of said hollow member and having aplurality of symmetrically-spaced peripheral holes each of whichcommunicates with the hollow interior of said member through a hole inthe wall of said hollow member, a plurality of tubes each of which isconnected between correspondingly-positioned holes in said manifoldstructures so as to communicate with said hollow interior of said memberand thus form a plurality of closed loop fluid flow conduitssymmetrically positioned with respect to said axis and each having anaxial branch in common with the other conduits each of 'said tubeshaving a first section extending radially outwardly from one of saidmanifolds, a second section extending back towards said axis at an acuteangle, a third section extending radially towards said axis, a fourthsection extending substantially parallel to said axis, a fifth sectionextending outwardly from said axis at an acute angle, a sixth sectionextending radially towards said axis, and a seventh section extendingtowards said axis at an acute angle and terminating in the other of saidmanifolds, first and second sets of annularly-shaped radial fins, thefirst in thermal contact with each of said second sections of saidtubes, and the second in thermal contact with each of said fifthsections of said tubes, each of said fins having a plurality ofperipherally spaced holes, a third set of radial fins in thermal contactwith said seventh section of each of said tubes and being shaped likefan blades, a casing for said apparatus, thermal insulating materialfilling said casing and surrounding said member and said tubes at allplaces other than those at which fins make thermal contact, andstationary gas conduit means adjacent said rotor for guiding warm andcool gases into and out of contact with said sets of fins and isolatingfrom one another the flows of gases past adjacent sets of fins.

34. Thermodynamic apparatus comprising, in combination, a rotor, ahollow member on the rotational axis of said rotor, a plurality ofradial spacers extending radially outwardly from said axial hollowmember and axially beyond each end of said member, a pair of end platessecured to the ends of said spacers and having axial projections toserve as drive and rotational support members,circumferentially-extending wall members extending between adjacentspacers to form generally sectorshaped fluid flow conduits and chambers,said wall members forming between each pair of spacers, a first conduitextending radially outwardly from and communicating -with one end ofsaid axial hollow member, a first chamber with an axially-extending4heat-conductive outer wall, a second conduit extending radially towardand thcn away from said axis, second and third chambers withcorresponding axially-extending heat-conductive outer walls, a fluidflow-restricting expansion nozzle connecting said second and thirdchambers, and a third conduit extending radially toward andcommunicating with the other end of said hollow member.

35. Apparatus as in claim 34 including `two sets of annular radial finsconnected to said first and second outer walls, said tins havingperipheral holes, a third set of fins connected to said third outer walland 'being shaped to form fan blades, means for guiding heated andcooled gases into and out of contact with said fins and isolating fromone another the flows of gases past adjacent sets of fins, said spacershaving holes in them where there are no conduits or chambers and beingmade of insulating material, further insulating material filling theinterior of said rotor outside of said hollow member and said conduitsand chambers.

36. A thermodynamic process comprising the steps of rotating a closedloop fluid conduit with a fluid therein, and creating a differencebetween the average density of said fluid along a first segment of fluidflowing outwardly from the axis of rotation of said conduit and theaverage density of said fluid along a second segment of fluid flowinginwardly toward said axis, said segments being of equal volume and beingspaced from said axis at equal distances, said densitydifference-creating step including heating said fluid at a firstposition located at a first radial distance from said axis, and coolingsaid fluid at a second radial distance, and pressurizing and thenexpanding said fluid to perform heat pumping.

37. A method as in claim 36 in which said differencecreating stepincludes making the fluid in one of said segments a liquid and the fluidin the other of said segments a gas.

38. A method as in claim 36 in which said second radial distance issmaller than said first radial distance.

39. Thermodynamic apparatus comprising, in combination, a rotor, meansfor rotating said rotor, conduit means in said rotor having a firstsection for guiding the flow of fluid radially outwardly from the axisof rotation of said rotor, and a second section connected to said firstsection at a location spaced radially outwardly from said axis, forguiding the flow of fluid back towards said axis, further conduit meansjoining said first and second conduit sections to conduct a fluidtherebetween at a second location which is spaced inwardly towards saidaxis from said first location, means for creating a continuousdifference between the average density of a first volume element offluid in said first section and a second volume element of fluid in saidsecond section, said first and second volume elements being equal andbeing located at equal average radial distances from said axis, saiddifference-creating means comprising means `for adding heat to saidfluid at a first location in said conduit, and means for extracting heatfrom said fluid at a second location in said condiut, the radialdistance of said first location from said axis being greater than theradial distance of said second location from said axis, and meansconnected to said conduit for pressurizing and then expanding the fluid.

References Cited UNITED STATES PATENTS 2,724,953 ll/ 1955 Justice 62-4992,924,081 2/1960 Justice 62*499 X 3,013,407 12/1961 Justice 62--4993,332,253 7/1967 Alexander 62-499 ROBERT A. OLEARY, Primary Examiner A.W. DAVIS, Assistant Examiner U.S. Cl. X.R. 62--499 UNITED STATES PATENTOFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,470 ,704 October 7 1965Frederick W. Kantor It is certified that error appears in the aboveidentified patent and that said Letters Patent are hereby corrected asshown below:

Column l0, line 36, claim reference numeral "3l" should read 2l Signedand sealed this 17th day of Merch 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, If

Edward M. Fletcher, Jr.

Commissioner of Patent Attesting Officer

